Theory of high-n toroidicity-induced shear Alfven eigenmode in tokamaks

Technical Report · Sat Jul 01 04:00:00 EDT 1989

OSTI ID:5840976

Fu, G Y; Cheng, C Z

High-n WKB-ballooning mode equation is employed to study toroidicity-induced shear Alfven eigenmodes (TAE) in the /delta/ /minus/ /alpha/ space, where /delta/ = (r/q)(dq/dr) is the magnetic shear, and /alpha/ = /minus/(2Rq/sup 2//B/sup 2/)(dp/dr) is the normalized pressure gradient for tokamak plasmas. In the ballooning mode first stability region, TAE modes are found to exist only for /alpha/ less than some critical value /alpha//sub c/. We also find that these TAE modes reappear in the ballooning mode second stability region for bands of /alpha/ values. The global envelope structures of these TAE modes are studied by WKB method and are found to be bounded radially if the local mode frequency has a maximum in radius. 15 refs., 14 figs.

• Research Organization: Texas Univ., Austin, TX (USA). Inst. for Fusion Studies
• DOE Contract Number: FG05-80ET53088; AC02-76CH03073
• OSTI ID: 5840976
• Report Number(s): DOE/ET/53088-385; IFSR-385; ON: DE89016726
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
ALFVEN WAVES
BALLOONING INSTABILITY
CLOSED PLASMA DEVICES
DIFFERENTIAL EQUATIONS
EQUATIONS
HYDROMAGNETIC WAVES
INSTABILITY
MAGNETIC FIELDS
PARTIAL DIFFERENTIAL EQUATIONS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PRESSURE GRADIENTS
SHEAR
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
WAVE EQUATIONS
WAVE PROPAGATION
WKB APPROXIMATION